Benzothiazolinylidene substituted ureas

ABSTRACT

Novel ureas and thioureas of the formula   WHERE X is oxygen or sulfur, R1 and R2 are alkyl radicals of not more than four carbon atoms, R3 is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the one and two carbon atoms, halophenyl of not more than five halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than four carbon atoms and not more than three halogen atoms therein, with the provision that the double bond in said alkenyl and cycloalkenyl are not in the 1-position. These compounds are useful as herbicides.

United States Patent Dixon 1 June 20, 1972 211 Appl. No.: 97,054

[52] US. Cl ..260/305, 71/90 [51 Int. Cl. 1 a ..C07d 91/24 [5 8] 'Field of Search ..260/ 305 [56] References Cited UNITED STATES PATENTS 2,616,894 1 1/1952 Derbyshire ..260/305 2,756,135 7/1956 Searle ...260/305 2,851,391 9/1958 Gerjovich et a1. ..260/305 3,499,902 3/1970 Coles et a1. ..260/305 Primary E.\'aminerAlex Mazel Assistant Examiner-R. J. Gallagher Attorney-Neal E. Willis, Paul C. Krizov and Harold M. Dixon [57] ABSTRACT Novel ureas and thioureas of the formula where X is oxygen or sulfur, R and R are alkyl radicals of not more than four carbon atoms, R;, is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the one and two carbon atoms, halophenyl of not more than five halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than four carbon atoms and not more than three halogen atoms therein, with the provision that the double bond in said alkenyl and cycloalkenyl are not in the 1-position.

These compounds are useful as herbicides.

15 Claims, No Drawings BENZOTHIAZOLINYLIDENE SUBSTITUTED UREAS BENZOTHIAZOLINYLIDENE SUBSTITUTED UREAS This invention relates to new ureas and thioureas. These new compounds are useful in controlling the growth of plants. The new compounds of this invention are of the formula where X is oxygen or sulfur, R and R are alkyl radicals of not more than four carbon atoms, R is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the l (or a) and 2 (or [3) carbon atoms, halophenyl of not more than five halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than four carbon atoms and not more than three halogen atoms therein, with the proviso that the double bond in said alkenyl and cycloalkenyl are not in the l-position.

Preferred compounds of this invention are those wherein X is sulfur or wherein R is alkyl or alkenyl and wherein X is sulfur and R is alkyl simultaneously. Other preferred embodiments are halophenyl radicals which have a maximum of three halogens on the phenyl ring.

The alkyl radicals represented by R and R can be straight or branched, primary, secondary or tertiary. For example, R, and R can each be methyl, ethyl, propyl, isopropyl, n-butyl, sec. butyl and tert. butyl.

The alkyl radicals represented by R can likewise be straight or branched, primary, secondary or tertiary. Examples are methyl, propyl, isopropyl, n-butyl, sec. butyl, isobutyl and tert. butyl, n-hexyl, isononyl, n-dodecyl and isododecyl.

Examples of alkenyl radicals represented by R are 2-propenyl, 2-butenyl, 2-isobutenyl, Z-hexenyl, 3-nonenyl, 2-dodecenyl.

Examples of cycloalkenyl radicals represented by R are 2- cyclohexenyl, 3-cyclohexenyl and 2-cyclooctenyl.

Examples of haloalkyl radicals represented by R are chloromethyl; trifluoromethyl; Z-bromoethyl; iodomethyl and 2,2,2,trifluorornethyl.

Examples of halophenyl radicals represented by R are 2- chlorophenyl; 2-fluorophenyl; 4-bromophenyl; 2-iodophenyl; 2,4-difluorophenyl and 2,4,6-trichlorophenyl.

Examples of haloalkylphenyl radicals represented by R are Z-trifluoromthylphenyl; 4-bromomethylphenyl; 4- iodomethylphenyl; 3-chloromethylphenyl and 3,5- di(trifluormethyl)phenyl.

Illustrative examples of the compounds of this invention are:

l-( 3 ,6-dimethyl-2-benzothiazolinylidene)-3-methylurea l-( 3-methyl,6tert,butyl-2-benzothiazolinylidene)-3- methylurea l-( 3 ,6-dimethyl-2-benzothiazolinylidene)-3-iso-dodecylurea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2-isobutenyl)area l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2-dodecenyl urea 1-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2-cyclohexenyl)urea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3- trifluoromethylurea l-( 3,6-dimethyl-2-benzothiazolinylidene )-3-methyl-2- thiourea 1-(3-methyl,6-tert.butyl-2-benzothiazolinylidene)-3- methyl-2-thiourea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-isopropyl-2- thiourea l 3 ,6-dimethyl-2-benzothiazolinylidene l-( 3,6-dimethyl-2-benzothiazolinylidene)-3-( 2-isobutenyl 2-thiourea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2-cyclohexenyl )-2-thiourea l-(3,6-dimethyl-2-benzothiazolinylidene)-3-chloromethylurea 1( 3 ,6-dimethyl-2-benzothiazolinylidene)-3-( 2,2,2-

trifluoroethyl)urea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2-fluorophenyl )-2-thiourea l-( 3,6-dimethyl-2-benzothiazolinylidene )-3-( 2,4-

dibromophenyl)-2-thiourea The compounds of this invention in general can be prepared by reacting the 3,6-dialkyl-2-benzothiazolinylirnine with the isocyanate or isothiocyanate corresponding to the structure desired as product although the iodoalkyl containing compounds are more suitably prepared by preparation of a corresponding difierent haloalkyl and then displacing the halo thereof with Na] in acetone at room temperature (i.e. about 20 C) and pressure (i.e. about 15 psi.).

The reaction will be made clear by the following detailed examples.

EXAMPLEI About 0.05 mole or 8.7 g. of 3,6-dimethyl-2- benzothiazolinylimine was dissolved in about 50 ml. of ether and was placed in a four-necked flask equipped with a thermometer, stirrer, condenser (using tap water) and a dropping funnel. About 0.05 mole or 3.7 g. of methylisothiocyanate was added dropwise to the solution in the flask. The reaction was noted to be slightly exothermic. The mixture was allowed to stand overnight and filtered. The yellow needles were recrystallized from about 300 ml. of acetonitrile and dried at about 100 C at 0.3 mm. Hg. An off-white powder melting at C H N S %C 7:H %N Calculated: 52.55 5.21 l6.7l 52.53 5.27 16.81

Found:

Nuclear magnetic resonance (NMR) spectral analysis confirmed the product l-(3,6-dimethyl-2-benzothiazolinylidene)- 3-methyl-2-thiourea.

EXAMPLE ll Using similar equipment as that in Example I, 0.05 mole or 8.7 g. of 3,6-dimethyl-2-benzothiazolinylimine was dissolved in about 150 ml. of ether and placed in the flask. About 0.05 mole or 9.4 g. of 3,4-dichlorophenylisocyanate dissolved in about 60 ml. of ether was added dropwise to the flask. The reaction was exothermic and solid product formed immediately. The solid was filtered and recrystallized from dimethylformamide. Recrystallized product dried at about l00 C at 0.2 mm. Hg. had a melting point of 2 l 6 2 1 8 C. Elemental analysis was as follows:

C H Cl N OS C 70H 7cll Calculated: 52.47 3.58 11.47 Found: 52.53 3.62 11.61

NMR spectral analysis confirmed the expected product 1- (3 ,4-dichlorophenyl-( 3,6-dimethyl-2-benzothiazolinyv l-(3,o-dimethyl-2-benzothiazolinylidene)-3-(2-fluorophen- 70 l yl )urea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 2,4-

dibromophenyl )urea l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-( 3- chloromethylphenyl )urea As aforementioned, the compounds of this invention are useful in controlling the growth of plants. This utility will now be discussed and exemplified.

The term herbicide as used herein and in the appended claims means materials which control the growth of plants either (1) all plants in a given locus or (2) selectively the growth of one or more plant species in the presence of other plants. In like manner, herbicidal" is used to identify the overall as well as the selective control activity of the compositions of this invention.

The term plant as used. herein and in the appended claims is inclusive of dormant seeds, germinant seeds, germinative seeds, emerging seedlings and established woody and herbaceous vegetation including the roots and above-ground portions.

The term control as used herein and in the appended claims is inclusive of the actions of (l) killing, (2) inhibiting growth, reproduction or proliferation, and (3) removing, destroying or otherwise diminishing the occurrence and activity of plants and is applicable to any of the stated actions, or any combination thereof.

The term "herbicidal formulation or composition" as used herein means at least one compound of this invention in com bination with an adjuvant.

EXAMPLE Ill The pre-emergent herbicidal activity of the active ingredients of this invention is demonstrated as follows: A good grade of top soil is placed in aluminum pans and compacted to a depth of three-eights to one-half inch from the top of each pan. A pre-determined number of seeds of the test plant species are placed on top of the soil in the pans. The seeds are covered with a three-eight inch layer of soil and the pan leveled. The active ingredient is applied by spraying it on the surface of the soil as a herbicidal formulation containing a sufficient amount of active ingredient to obtain the desired rate of active ingredient per acre.

The seed-containing pans are placed on a sand bench and maintained under ordinary conditions of sunlight and watering. The plants are observed at the end of approximately 14 days and the results recorded. The herbicidal activity index is based on the average percent control of each seed lot. The herbicidal activity index is converted to a relative numerical scale for the sake of brevity and simplicity in the table.

The pre-emergent herbicidal activity index used is defined as follows:

Average Percent Numerical Control Scale to 25 0 26 to 50 l 51 to 75 2 76 to I00 3 In foliar treatment of the modification of vegetative growth, the active ingredients are applied in amounts from about 1.0 to about 50 or more pounds per acre, preferably about 0.1 to l5 pounds per acre in foliar treatments. In soil applications, it is desirable that the active ingredients be distributed to a depth of at least 0.2 inches. In pre-emergence herbicidal applications the active ingredients are usually applied in amounts from about 0.1 to 25 pounds per acre but preferably from about 1.0 to 10 pounds per acre. It is believed that one skilled in the art can readily determine from the teachings of this specification, including examples, the procedure for any particular desired application.

In using the compounds of this invention, the active ingredients can be used along or in combination with a material referred to in the art as an adjuvant in liquid or solid form. The usual purpose of adjuvants is to facilitate application of the herbicidal composition and to obtain the desired dosage rate. Herbicidal formulations are prepared by admixing the active ingredient with one or more adjuvant which includes diluents, extenders, carriers and conditioning agents to provide com positions in the form of finely-divided particulate solids, granules, pellets, solutions, dispersions or emulsions. Thus, the active ingredient can be used with an adjuvant such as a finelydivided particulate solids, granules, pellets, solutions, dispersions or emulsions. Thus, the active ingredient can be used with an adjuvant such as a finely-divided particulate solid, a liquid of organic origin, water, a wetting agent, dispersing agent, an emulsifying agent or any suitable combination of these.

Suitable adjuvants of the foregoing types are not here defined in detail as to composition, particle size, relative amounts etc. since they are well known in the art.

In general, the active ingredients may be formulated with the active ingredient in minor or major proportions in accordance i he. le be ow;

Concentration of In addition to adjuvants the compounds of this invention can be used in combination with fertilizers and/or other pesticides such as insecticides, fungicides, nematocides, and/or other phytotoxicants inclusive of herbicides, and the like.

TABLE I Dosage, Canada Cockle- Velvet Morning Lambs- Smart- Nut- Quack- Johnson Downy Barnyard Compound lbJacre thistle bur leaf glory quarter weed sedge grass grass brome grass 0 0 0 2 0 0 2 1 1 O 0 l (l O 0 0 0 1 0 1 O 2 0 0 0 0 A l-( 3 ,6-dimethyl-2-benzothiazolinylidene )-3-methyl-2- thiourea B =l 3 ,4-dichlorophenyl )-3-( 3 ,6-dimethyl-2- Having now described the invention, many ramifications and modified embodiments will readily occur to those skilled in the art. In so far as such variations do not depart from the spirit and scope of theinvention described in this application, they are intended to be embraced by the appended claims in their broadest construction.

What is claimed is:

l. A compound of the formula where X is oxygen or sulfur, R and R are alkyl radicals of not more than four carbon atoms, R is alkyl of not more than 12 carbon atoms, alkenyl of not more than 12 carbon atoms, cycloalkenyl of six through eight carbon atoms, haloalkyl of not more than 12 carbon atoms and with not more than three halogen atoms therein on the one and two carbon atoms, halophenyl of not more than five halogen atoms, haloalkylphenyl of not more than three haloalkyls having not more than 4 carbon atoms and not more than three halogen atoms therein, with the proviso that the double bond in said alkenyl and cycloalkenyl are not in the l-position.

2. A compound according to claim 1 wherein X is sulfur.

3. A compound according to claim 1 wherein X is oxygen.

4. A compound according to claim 1 wherein R is alkyl.

5. A compound according to claim 1 wherein R is alkenyl.

6. A compound according to claim 1 wherein R is halophenyl with up to three halogens therein.

7. A compound according to claim 2 wherein R is alkenyl. 8. A compound according to claim 2 wherein R is cycloalkenyl.

9. A compound according to claim 2 wherein R is 5 halophenyl.

10. A compound according to claim 3 wherein R; is alkenyl. 11. A compound according to claim 3 wherein R is cycloalkenyl.

12. A compound according to claim 3 wherein R; is 10 halophenyl.

13. A compound according to claim I which is l-(3,6- dimethyl-2-benzothiazolinylidene)-3-methyl-2-thiourea.

14. A compound according to claim 1 which is l-(3,4- dichlorophenyl)-3-(3,6-dimethyl-2-benzothiazolinylidene)urea.

15. A compound according to claim 1 which is 1-methyl-3- (3,6-dimethyl-2-benzothiazolin'ylidene)urea.

t t II: 

2. A compound according to claim 1 wherein X is sulfur.
 3. A compound according to claim 1 wherein X is oxygen.
 4. A compound according to claim 1 wherein R3 is alkyl.
 5. A compound according to claim 1 wherein R3 is alkenyl.
 6. A compound according to claim 1 wherein R3 is halophenyl with up to three halogens therein.
 7. A compound according to claim 2 wherein R3 is alkenyl.
 8. A compound according to claim 2 wherein R3 is cycloalkenyl.
 9. A compound according to claim 2 wherein R3 is halophenyl.
 10. A compound according to claim 3 wherein R3 is alkenyl.
 11. A compound according to claim 3 wherein R3 is cycloalkenyl.
 12. A compound according to claim 3 wherein R3 is halophenyl.
 13. A compound according to claim 1 which is 1-(3,6-dimethyl-2-benzothiazolinylidene)-3-methyl-2-thiourea.
 14. A compound according to claim 1 which is 1-(3,4-dichlorophenyl)-3-(3,6-dimethyl-2-benzothiazolinylidene)urea.
 15. A compound according to claim 1 which is 1-methyl-3-(3,6-dimethyl-2-benzothiazolinylidene)urea. 